better prevention of auto repack

Looking through the git sources (documentation is unclear),
it seems commit doesn't ever trigger git-gc, mostly fetching and merging
seems to. I cannot easily override the setting in all those places, so
instead set gc.auto in git config when initializing a repository with
the assistant.

This does mean that the user cannot set gc.auto=0 and completely avoid
repacks, as the assistant does it daily. But, it only does it after there
are 100x the default number of loose objects, so this is probably not going
to be too annoying.

Assistant/Threads/Committer.hs

@@ -82,8 +82,7 @@ commitStaged = do
 		Right _ -> do
 			direct <- isDirect
 			let params = nomessage $ catMaybes
-				[ Just $ Param "-c", Just $ Param "gc.auto=0"
-				, Just $ Param "commit"
+				[ Just $ Param "commit"
 				, Just $ Param "--quiet"
 				{- In indirect mode, avoid running the
 				 - usual git-annex pre-commit hook;

Assistant/Threads/SanityChecker.hs

@@ -15,6 +15,7 @@ import Assistant.DaemonStatus
 import Assistant.Alert
 import qualified Git.LsFiles
 import qualified Git.Command
+import qualified Git.Config
 import Utility.ThreadScheduler
 import qualified Assistant.Threads.Watcher as Watcher
 import Utility.LogFile
@@ -85,8 +86,16 @@ dailyCheck = do
 	liftIO $ void cleanup
 
 	{- Allow git-gc to run once per day. More frequent gc is avoided
-	 - to avoid slowing things down. -}
-	void $ liftIO $ Git.Command.runBool [Param "gc", Param "--auto"] g
+	 - by default to avoid slowing things down. Only run repacks when 100x
+	 - the usual number of loose objects are present; we tend
+	 - to have a lot of small objects and they should not be a
+	 - significant size. -}
+	when (Git.Config.getMaybe "gc.auto" g == Just "0") $
+		liftIO $ void $ Git.Command.runBool
+			[ Param "-c", Param "gc.auto=670000"
+			, Param "gc"
+			, Param "--auto"
+			] g
 
 	return True
   where

Assistant/WebApp/Configurators/Local.hs

@@ -302,9 +302,9 @@ initRepo primary_assistant_repo dir desc = inDir dir $ do
 	{- Initialize a git-annex repository in a directory with a description. -}
 	unlessM isInitialized $
 		initialize desc
+	{- Initialize the master branch, so things that expect
+	 - to have it will work, before any files are added. -}
 	unlessM (Git.Config.isBare <$> gitRepo) $
-		{- Initialize the master branch, so things that expect
-		 - to have it will work, before any files are added. -}
 		void $ inRepo $ Git.Command.runBool
 			[ Param "commit"
 			, Param "--quiet"
@@ -312,8 +312,15 @@ initRepo primary_assistant_repo dir desc = inDir dir $ do
 			, Param "-m"
 			, Param "created repository"
 			]
-	when primary_assistant_repo $
+	{- Repositories directly managed by the assistant use direct mode.
+	 - 
+	 - Automatic gc is disabled, as it can be slow. Insted, gc is done
+	 - once a day.
+	 -}
+	when primary_assistant_repo $ do
 		setDirect True
+		inRepo $ Git.Command.run
+			[Param "config", Param "gc.auto", Param "0"]
 	getUUID
 
 {- Adds a directory to the autostart file. -}

debian/changelog

@@ -9,9 +9,10 @@ git-annex (4.20130228) UNRELEASED; urgency=low
     files in direct mode repositories.
   * assistant: Fix dropping content when a file is moved to an archive
     directory.
-  * assistant: Prevent automatic commits from causing git-gc runs,
-    as that can make things quite slow. Instead, git-gc --auto is run
-    once a day. (This can be disabled by the usual gc.auto=0 setting.)
+  * assistant: Set gc.auto=0 when creating repositories to prevent
+    automatic commits from causing git-gc runs.
+  * assistant: If gc.auto=0, run git-gc once a day, packing loose objects
+    very non-aggressively.
 
  -- Joey Hess <joeyh@debian.org>  Wed, 27 Feb 2013 23:20:40 -0400